138 CANNON: STUDIES IN PLANT HYBRIDS 
among themselves and produce offspring the a characters are seen, 
and in a definite proportion to the form bearing the 4 characters. 
These constitute the hybrids of the second generation. If now 
the hybrids of the second generation are fertilized in such a man- 
ner that plants with @ characters are crossed with those bearing 
the same characters, and likewise plants bearing A characters with 
forms like themselves, the resulting hybrids will behave in a man- 
ner characteristic of the respective cross, That is (1) the plants 
with @ characters will be found to transmit those characters only, 
7, e. they are “ fixed”’ ; and (2) when the plants with 4 characters 
are fertilized with other plants bearing the same characters, that is 
to say, if inbred, two sorts of hybrids will result : one portion will 
bear only the 4 characters, which may be demonstrated by breed- 
ing as before, and one portion, apparently also with 4 characters 
only, will be found to vary just as the hybrids of the primary cross 
varied, z. e. this will be really mixed or hybrid. This general 
scheme may be better understood if tabulated as follows : 
Generations I Il Ill IV 
Parent a — : Wea ea ak Be ea tas a Beda ie ete. 
(male or 
female). 
RUischsaveclveteevse Fy ARREARS cir ete 
, if 
ia A(a) aA lS) sie SHOUD Biv tin ele, 
: 3 
‘ BAH eck ee es eee Ae a ae elt 
Parent 4 — $4 ee ees a F wegeeie) ete. 
(male or 
Jemale),. 
Fic. 1. Explanation: A, dominant character; a, recessive character; 4 (a), 
a hybrid having both characters of which (a) is masked by A. 
Not only do the hybrids vary thus in a regular manner, but 
there is also a definite proportion of recessives (a), and dominants 
(A), as the table indicates. That is, referring to the table, in the 
second generation one fourth of the offspring is recessive (a), and 
three fourths apparently dominant (A), but really composed of two 
sorts (A(a)) one third of these being dominant (A), two thirds 
mixed(A (a) ). The latter continue in the succeeding generation to 
vary just as the hybrids of the primary cross varied, one fourth of 
